Dispensable, viscous materials such as adhesives, epoxies, sealants, including caulking, pastes, lubricants, and other viscous materials are typically packaged in rigid, thermoplastic tubular containers, or spiral bound cardboard tubes. To some extent, although not as often, some of these viscous materials come pre-packaged in tubular, sausage type containers having a relatively strong, but flexible outer impermeable skin to encapsulate the viscous material.
The rigid containers are often provided with pre-attached nozzle tips made from a thermoplastic material that is sealed against entry of air and to prevent the viscous material from escaping from the container. An air seal may be provided between the main portion of the tube containing the viscous material, and the base of the hollow nozzle tip. A user will typically cut away a portion of the nozzle tip, to create an opening to dispense the viscous material, and then will pierce the air seal (through the newly created opening), so that when in use, the viscous material will enter the channel of the hollow nozzle and exit from the cut opening at the nozzle tip. The user will then try to carefully apply sufficient pressure to the contents of a caulking gun or other dispensing device to apply a uniform bead of material to a target surface. The inability to apply an uniform bead is a common problem associated with hand operated caulking guns, and powered dispensers fitted with conventional nozzles, including aerosol containers filled with dispensable materials such as caulking or other sealants.
Unfortunately, it is relatively difficult for inexperienced users and many trained workers to apply uniform beads of material over extended periods of time. Conventional hand operated devices are prone to significant variations in bead quality and appearance. Even if an operator is provided with a conventional, powered dispensing device, it is difficult for the operator to control the flow rate at which the viscous material is dispensed and deposited to a target area.
One of the most common types of existing tubular container designs includes the fixed, hollow nozzle tip made from polyethylene or other thermoplastic material, briefly described above. The nozzle tip is fixed to the container, and if the affixed, conventional nozzle tip is spoiled, plugged, or rendered unusable, the entire container must be thrown away because the user will not have a convenient, cost effective replacement for the spoiled nozzle tip. Furthermore, the prefixed nozzles are not provided with replaceable or interchangeable nozzle tips. Essentially, a user is not provided with a selection of interchangeable tips that could be used to dispense different shapes and sizes of beads.
There are many other disadvantages to using known conventional nozzle designs and conventional dispensing devices. By way of further example, but not by way of limitation, prefixed nozzles cannot be removed for cleaning and cannot be reused. Once the container is emptied, the container and the nozzle tip are discarded. There are also other disadvantages associated with prefixed nozzles in that the overall container size is greatly increased by the added length of the prefixed nozzle component. The added length makes it necessary for manufacturers and others to package the containers in relatively large boxes to accommodate the added space occupied by the nozzles. If the nozzle of a container is damaged during shipping or handling, the entire damaged container and its contents are typically discarded, resulting in significant losses and higher costs. Earlier nozzle designs of this type are not readily adaptable for use in dispensing viscous materials from sausage type containers. Furthermore, these conventional nozzle designs do not provide features to control the flow rate for dispensing the viscous materials from lightweight hand held dispensing devices, including caulking guns.